Zealously created ten layers (9)
I believe the answer is:
earnestly
'zealously' is the definition.
(I've seen this before)
'created ten layers' is the wordplay.
'created' indicates anagramming the letters (I've seen 'create' mean this).
'ten'+'layers'='tenlayers'
'tenlayers' with letters rearranged gives 'EARNESTLY'.
(Other definitions for earnestly that I've seen before include "Sincerely and seriously" , "Relent, say, in sincere and serious manner" , "how Wilde character may be acted?" , "In all seriousness" , "Showing commitment" .)